H5N1 Virus in Cattle Raises Concerns Over Human Infection Risk

Health experts are closely monitoring the H5N1 avian influenza virus. This is the first time they detected this virus in dairy cattle in the United States. The discovery of this virus in cows has raised alarms about its possible adaptation to humans. Richard Webby, one of the leading avian influenza researchers at St. Jude Children’s Research Hospital, released some startling findings. He recently brought his work to the World Vaccine Congress in Washington on April 23.

Just last year, H5N1 was found in cow’s milk, a finding that bodes horribly for how this decades-long battle with the virus continues to unfold. The main form of H5N1 transmission is still through birds, this recent detection in cattle introduces a different degree of concern. In all, 70 people in the United States have been infected with different strains of H5N1. Perhaps most concerning, 41 of these cases are tied to exposure to dairy herds.

One of those fatal cases was of a man who died after infection with a variant strain of H5N1. The person had very close contact with backyard chickens and wild birds where illness was manifested. This interaction highlights the persistent threat that the virus continues to pose to avian populations. Webby and other experts, including BTI’s Evans, warn that the dynamic might be changing.

Webby stressed that cattle production, by virtue of its structure, is a perfect environment for the virus to persist. And since cattle have the same types of sialic acid attachments in their cells as humans do, infection with the virus is enabled. “This is like a ‘kid in a candy store’ if you’re a virus in the udders of these cows,” he stated.

The ability of H5N1 to infect marine mammals further complicates the already complex scenario. Until recently, scientists thought that these animals were immune to bird flu. This surprising finding has sent up warning flares about the virus’s ingenuity and adaptability.

Experts are worried as they watch what H5N1 is doing in cattle. They urge continued surveillance and research to provide a clearer picture of this virus’ effects. Webby noted, “It’s just that there’s so much more virus around,” indicating that the spread may increase.